In the drilling and completion industry, the formation of boreholes for the purpose of production or injection of fluid is common. The boreholes are used for exploration or extraction of natural resources such as hydrocarbons, oil, gas, water, and alternatively for CO2 sequestration. Downhole production boreholes utilized in subterranean operations typically utilize casings disposed therein, along with zonal isolation material which may be cement in some cases, to protect the borehole from downhole pressures, chemical reactions and other conditions and prevent failures such as borehole collapse, burst, and tensile failures. Casing can also be used to define production zones in various portions of the borehole.
Casing and zonal isolation material monitoring and evaluation techniques are important tools in maintaining the integrity of the zonal isolation, and in turn maintaining the integrity of the borehole. Evaluation and maintenance procedures involve interrogating the casing and cement that is used to bond the casing to a borehole wall to determine whether voids are present between the casing and the borehole wall. Well logging tools are utilized to make the interrogation, such as wireline tools that convey an interrogator inside of the casing to the location for interrogation. Such wireline tools require personnel to deliver the tool for interrogation and retrieve the tool subsequent completion of an interrogation operation. Interpretation of the log may then be occur.
The art would be receptive to alternative devices and methods for casing, zonal isolation monitoring and improvements to casings.